Fastening devices of one type as are commonly used for retaining movable canvas covers or the like comprise a base portion and a key portion upstanding therefrom and mounted for rotation about a central axis. The base portion is provided with a plurality of detents and the key portion with one or more shaped elements which are biased into contact with the detents by a spring. Generally speaking such fastening devices are exposed to the weather, and their structure is such that rain water is channeled into the moving parts, where it collects in the hollow base. This leads to rotting of the underlying support structure and rusting of the fastener components. A further deficiency of the above fasteners resides in the locating mechanism for the key portion. When the key portion is not fully engaged in detents, the biasing spring is compressed. The base structure intermediate the detents is cam like, and the shaped elements of the key portion are urged therealong by the force of the biasing spring. Assuming the key portion to be positioned half-way between adjacent detents, it may then revert to a position wherein it releases the cover.
It is then an object of my invention to provide a fastener device of improved reliability of operation.
It is a further object of my invention to provide a fastener device of simplified structure.
It is yet another object of my invention to provide a fastener device of reduced cost.